As part of continuing efforts to increase the speed and functionality of integrated circuits (ICs) such as central processing units (CPUs), there has been a continuing need to dissipate ever greater quantities of heat generated by such ICs during normal operation. This has required the use of heatsinks of ever larger design and using materials that are ever more effective at conducting heat away from such ICs (e.g., substituting copper for aluminum). The result has been that heatsinks have become heavier and heavier.
Until recently, it was acceptable to use a “spring clip” of a type that held a surface of a heatsink in contact with a surface of such ICs by hooking onto plastic tabs molded into the sides of the sockets in which such ICs were installed. Early on, for small and lightweight heatsinks (often made of aluminum), the plastic tabs proved to be more than adequate to retain a heatsink in contact with such ICs. However, as heatsinks have become necessarily heavier, this use of plastic tabs has been deemed undesirable, because the plastic material is often to not be strong enough to resist breaking, shearing or resisting other catastrophic failure when shock or vibration causes a heavier heatsink to be ripped away from contact with such ICs. Such mechanisms also often did not retain a heatsink in contact with such an IC with an even distribution of force across the area of contact between the heatsink and the package of such an IC with the result that the effectiveness of the conduction of heat from the IC to the heatsink could be compromised.
To improve upon the use of plastic tabs and a spring clip, it has become common practice to form a set of holes through the circuitboard around the location at which sockets for such ICs are attached to the circuitboard, and using a combination of threaded fasteners including nuts, bolts and/or plates with threaded holes to retain heavier heatsinks in contact with such ICs. However, with such approaches installing or removing a heatsink often requires the use of a screwdriver or other tools, and often requires that the circuitboard be removed from the chassis into which it is installed to gain access to the side opposite of that to which the socket is attached in order to tighten or loosen such threaded fasteners.
In some cases where plates with threaded holes are employed, the plate is shaped so as to press against the circuitboard at a location underneath the socket for the IC on the side opposite that to which the socket is attached. Unfortunately, the shape of some of these plates and the manner in which they are engaged by bolts can cause the plate to induce warpage of the circuitboard if an IC is not installed in the socket. Such a use of threaded fasteners also often requires that the person installing a heatsink must make an effort to tighten each of the bolts with a similar amount of torque so that the heatsink will be retained in contact with the IC with an even distribution of force across the area of contact between the heatsink and the package of the IC. This may pose little problem where a person of some skill undertakes to do the tightening of the bolts, but this can become highly problematic where an unskilled end user of an electronic device into which the IC and heatsink are being installed undertakes to do this tightening. There is also a risk that one or more bolts could be overtightened, resulting in damage to the IC and/or the circuitboard.